LineSegmentGenerators.h

Go to the documentation of this file.

// Copyright Epic Games, Inc. All Rights Reserved.
 
#pragma once
 
#include "CoreMinimal.h"
#include "VectorTypes.h"
#include "FrameTypes.h"
#include "TransformTypes.h"
 
namespace UE
{
    namespace Geometry
    {
        using namespace UE::Math;
 
        template<typename RealType>
        void GenerateBoxSegments(
            const TVector<RealType>& HalfDimensions, 
            const TVector<RealType>& Center, 
            const TVector<RealType>& AxisX, 
            const TVector<RealType>& AxisY, 
            const TVector<RealType>& AxisZ,
            const TTransformSRT3<RealType>& Transform,
            TFunctionRef<void(const TVector<RealType>& A, const TVector<RealType>& B)> EmitLineFunc);
 
        template<typename RealType>
        void GenerateCircleSegments(
            int32 NumSteps, 
            RealType Radius, 
            const TVector<RealType>& Center,
            const TVector<RealType>& AxisX,
            const TVector<RealType>& AxisY,
            const TTransformSRT3<RealType>& Transform,
            TFunctionRef<void(const TVector<RealType>& A, const TVector<RealType>& B)> EmitLineFunc);
 
        template<typename RealType>
        void GenerateArcSegments(
            int32 NumSteps, 
            RealType Radius,
            RealType StartAngle, 
            RealType EndAngle,
            const TVector<RealType>& Center,
            const TVector<RealType>& AxisX,
            const TVector<RealType>& AxisY,
            const TTransformSRT3<RealType>& Transform,
            TFunctionRef<void(const TVector<RealType>& A, const TVector<RealType>& B)> EmitLineFunc);
    }
}
 
 
 
 
 
template<typename RealType>
void UE::Geometry::GenerateBoxSegments(
    const TVector<RealType>& HalfDimensions,
    const TVector<RealType>& Center,
    const TVector<RealType>& AxisX,
    const TVector<RealType>& AxisY,
    const TVector<RealType>& AxisZ,
    const TTransformSRT3<RealType>& Transform,
    TFunctionRef<void(const TVector<RealType>& A, const TVector<RealType>& B)> EmitLineFunc)
{
    // B is box max/min, P and Q are used to store the start and endpoints of the segments we create
    TVector<RealType>   B[2], P, Q;
    B[0] = Center + HalfDimensions; // max
    B[1] = Center - HalfDimensions; // min
 
    // Iterate across the four corners of top/side/front and create segments along the Z axis
    for (int32 i = 0; i < 2; i++)
    {
        for (int32 j = 0; j < 2; j++)
        {
            P.X = B[i].X; Q.X = B[i].X;
            P.Y = B[j].Y; Q.Y = B[j].Y;
            P.Z = B[0].Z; Q.Z = B[1].Z;
            EmitLineFunc(Transform.TransformPosition(P), Transform.TransformPosition(Q));
 
            P.Y = B[i].Y; Q.Y = B[i].Y;
            P.Z = B[j].Z; Q.Z = B[j].Z;
            P.X = B[0].X; Q.X = B[1].X;
            EmitLineFunc(Transform.TransformPosition(P), Transform.TransformPosition(Q));
 
            P.Z = B[i].Z; Q.Z = B[i].Z;
            P.X = B[j].X; Q.X = B[j].X;
            P.Y = B[0].Y; Q.Y = B[1].Y;
            EmitLineFunc(Transform.TransformPosition(P), Transform.TransformPosition(Q));
        }
    }
}
 
 
 
template<typename RealType>
void UE::Geometry::GenerateCircleSegments(
    int32 NumSteps, RealType Radius,
    const TVector<RealType>& Center,
    const TVector<RealType>& AxisX,
    const TVector<RealType>& AxisY,
    const TTransformSRT3<RealType>& Transform,
    TFunctionRef<void(const TVector<RealType>& A, const TVector<RealType>& B)> EmitLineFunc)
{
    TVector<RealType> PrevPos = TVector<RealType>::Zero();
    for (int32 i = 0; i <= NumSteps; ++i)
    {
        RealType t = (RealType)i / (RealType)NumSteps;
        RealType Angle = (RealType)2.0 * TMathUtil<RealType>::Pi * t;
        RealType PlaneX = Radius * TMathUtil<RealType>::Cos(Angle);
        RealType PlaneY = Radius * TMathUtil<RealType>::Sin(Angle);
        TVector<RealType> CurPos = Transform.TransformPosition(Center + PlaneX * AxisX + PlaneY * AxisY);
        if (i > 0)
        {
            EmitLineFunc(PrevPos, CurPos);
        }
        PrevPos = CurPos;
    }
}
 
 
 
template<typename RealType>
void UE::Geometry::GenerateArcSegments(
    int32 NumSteps,
    RealType Radius,
    RealType StartAngle,
    RealType EndAngle,
    const TVector<RealType>& Center,
    const TVector<RealType>& AxisX,
    const TVector<RealType>& AxisY,
    const TTransformSRT3<RealType>& Transform,
    TFunctionRef<void(const TVector<RealType>& A, const TVector<RealType>& B)> EmitLineFunc)
{
    TVector<RealType> PrevPos = TVector<RealType>::Zero();
    for (int32 i = 0; i <= NumSteps; ++i)
    {
        RealType t = (RealType)i / (RealType)NumSteps;
        RealType Angle = ((RealType)1 - t) * StartAngle + (t)*EndAngle;
        RealType PlaneX = Radius * TMathUtil<RealType>::Cos(Angle);
        RealType PlaneY = Radius * TMathUtil<RealType>::Sin(Angle);
        TVector<RealType> CurPos = Transform.TransformPosition(Center + PlaneX * AxisX + PlaneY * AxisY);
        if (i > 0)
        {
            EmitLineFunc(PrevPos, CurPos);
        }
        PrevPos = CurPos;
    }
}